From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753389Ab3AXNOS (ORCPT ); Thu, 24 Jan 2013 08:14:18 -0500 Received: from cpsmtpb-ews07.kpnxchange.com ([213.75.39.10]:65357 "EHLO cpsmtpb-ews07.kpnxchange.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750975Ab3AXNOJ (ORCPT ); Thu, 24 Jan 2013 08:14:09 -0500 Message-ID: <1359033178.1325.15.camel@x61.thuisdomein> Subject: [PATCH] acer-wmi: do not use 'devices' uninitialized From: Paul Bolle To: "Lee, Chun-Yi" , Matthew Garrett Cc: platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 24 Jan 2013 14:12:58 +0100 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4 (3.4.4-2.fc17) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-OriginalArrivalTime: 24 Jan 2013 13:12:59.0037 (UTC) FILETIME=[87FD24D0:01CDFA34] X-RcptDomain: vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit f20aaba9819d0801fb1314363f97239da0100bac ("acer-wmi: fix obj is NULL but dereferenced") introduced a GCC warning: drivers/platform/x86/acer-wmi.c: In function ‘acer_wmi_init’: drivers/platform/x86/acer-wmi.c:1216:14: warning: ‘devices’ may be used uninitialized in this function [-Wmaybe-uninitialized] drivers/platform/x86/acer-wmi.c:1193:6: note: ‘devices’ was declared here GCC is correct. In WMID_set_capabilities() there are now clearly codepaths that use 'devices' uninitialized. (WMID_set_capabilities() is apparently inlined in acer_wmi_init().) Previously that couldn't happen. So rework the code to use the previous logic, but also make sure 'obj' will not be dereferenced while NULL. Signed-off-by: Paul Bolle --- Compile tested only! drivers/platform/x86/acer-wmi.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c index afed701..0ddac19 100644 --- a/drivers/platform/x86/acer-wmi.c +++ b/drivers/platform/x86/acer-wmi.c @@ -1197,14 +1197,12 @@ static acpi_status WMID_set_capabilities(void) return status; obj = (union acpi_object *) out.pointer; - if (obj) { - if (obj->type == ACPI_TYPE_BUFFER && + if (obj && obj->type == ACPI_TYPE_BUFFER && (obj->buffer.length == sizeof(u32) || obj->buffer.length == sizeof(u64))) { devices = *((u32 *) obj->buffer.pointer); - } else if (obj->type == ACPI_TYPE_INTEGER) { + } else if (obj && obj->type == ACPI_TYPE_INTEGER) { devices = (u32) obj->integer.value; - } } else { kfree(out.pointer); return AE_ERROR; -- 1.7.11.7